I'm really not sure where to place this but if I could ask somewhat of a logistical question, in a case where activity is found in the soft tissues, without corresponding anatomic abnormalities on a CT scan, how can radiotherapists adequately plan treatment and target such an area?

Would this be based on the results of a PET scan as, assumedly, a CT scan alone would be of little benefit in the planning stages? Or is radiotherapy to soft tissues impossible?

My father is considering radiotherapy for the soft-tissues lateral to his right hip following treatment for triple hit non-hodgkins lymphoma, as his PET-CT scan post 6 cycles of EPOCH was clear in all areas bar a tiny focus of uptake in these soft tissues.

We are also concerned about the possibility of secondary malignancies following radiotherapy to an area such as this,